The system is designed on a modular concept with two thermal vacuum chamber (TV) elements. The TV chamber has a usable diameter of 5 meters and a length of 14 meters. Below, the optical bench extends into both ISO-5 areas. Individually controlled thermal walls (shrouds) on the chamber's interior walls create a highly stable thermal environment. The TV chamber is connected to the hall floor and spans the spring-mounted optical bench, yet both remain vibration-decoupled from each other.

The Optical Ground Support Equipment (OGSE) comprises the primary OGSE for characterising the test objects and the secondary OGSE for aligning and monitoring the OGSE and the test object. Optical performance can be characterised under ambient or vacuum conditions while meeting ISO 5 cleanliness requirements. Two test configurations are available:

• OGSE provided by IABG
  For optical instruments with large apertures, the OGSE is positioned inside the TV chamber to minimise disturbances, for example from optical windows or ambient conditions. For this purpose, both chamber elements are connected in the long configuration.

• OGSE provided by the customer
  For instruments with small apertures, the OGSE can be installed outside the TV chamber on the same optical bench. A darkroom between the ISO 5 South area and the chamber lid allows the OGSE to be operated, while a suitable optical window provides a clear view of the test object inside the chamber.

Two spring-mounted masses, known as Optical Bench Installations (OBI), are integrated into the floor of the ISO 8 test hall to ensure vibration decoupling in accordance with VDI 2038 VC-E. The first spring-mounted mass (OBI 1) supports the TV chamber above it. Each optical bench segment provides a usable area of 2.6 m x 6.8 m with an 80 mm x 80 mm mounting grid. The maximum load capacity, including the test specimen and equipment, is 6,000 kg.